A federal appeals court has reinstated most of the claims of dog owners who sued animal control officials in Louisville, Ky., for implanting microchips in their nine dogs without consent.

The suit by James and Angela O’Neill claims animal control officers entered their home without a warrant, seized two adult bulldogs and seven puppies, spayed and neutered the adult dogs, and implanted microchips in all the animals. The O’Neills had to pay $1,000 to retrieve the dogs.

The Volokh Conspiracy has printed the opening paragraphs of today’s opinion (PDF) by the Cincinnati-based 6th U.S. Circuit Court of Appeals. “This is perhaps the dog-gonest case ever to reach a federal appellate court,” the opinion begins.

Two undercover animal control officers had posed as puppy buyers responding to a newspaper ad when they visited the O’Neills a day before Halloween in 2008. After seeing the puppies, the undercover officers stepped outside, and then returned with several animal control officers who seized the dogs over the O’Neills’ objections.

City officials had claimed the O’Neills were operating an unlicensed kennel. The 6th Circuit disagreed and allowed the couple’s claims for violations of Fourth Amendment and procedural due process rights. The court said tort law and immunity issues should be decided on remand.